Conventional map information processing apparatuses such as car navigation systems have realized a function to present information and the like relating to a map region that is being displayed on a screen. Examples thereof include a function to search for a gas station within a certain distance from the present location.
Furthermore, as a second conventional technique, a function is provided for an online map on the web and the like, in which information (information of restaurants, traffic facilities, etc.) relating to a currently displayed local area is presented as additional information (see Non-Patent Document 1, for example).
Furthermore, as a third conventional technique, there is a technique that enables a user to easily change the region and the scale of a map on a screen that the user is watching, with an operation on the online map (see Non-Patent Document 2, for example).
Furthermore, as a fourth conventional technique, there is a technique that enables web search to be performed in view of geography, by providing the content of a currently existing web page with a geographical structure, and associating it with the geographic coordinates in a real space (see Non-Patent Documents 3 and 4).
Furthermore, as a fifth conventional technique, there is a technique that visually expresses information distribution, using a method in which images transmitted by users to a server are attached to a map based on added positional information (see Non-Patent Document 5).
Furthermore, as a sixth conventional technique, there is a technique that enables blog search to be more effectively performed, by dividing keywords in blogs into ‘targets’ for the purpose of which many people travel and ‘experiences’ of people, based on the collocational relationship between the geographical or landmark name and the particle (see Non-Patent Document 6).
Furthermore, as a seventh conventional technique, there is a technique that enables a user to passively browse local information on the web along a route, by drawing the route on a map. A web page that is displayed on a system provided with this technique is determined according to the level of geographical significance calculated in advance. Furthermore, the level of detail of information that is to be presented is changed according to a zoom-in or zoom-out operation performed by the user on the map. If the user performs a zoom-out operation, a web page that contains keywords with high level of geographical significance is displayed. If the user performs a zoom-in operation, it is regarded that the user wants more detailed information of that local region, and a web page that contains keywords with low level of geographical significance is displayed (see Non-Patent Documents 7 and 8). In this technique, a purpose of the user is presumed based on only a single user operation on the map, and information is retrieved.
Furthermore, as an eighth conventional technique, there is a system that presents on-screen maps that are different for operations of individuals, based on a single map operation of a user (see Non-Patent Document 9).
Moreover, as a related technique, there is a technique of a so-called MBR (minimum bounding rectangle) described later (see Non-Patent Document 10).
[Non-Patent Document 1] Its-mo Guide, the Internet <URL:http://www.its-mo.com/>
[Non-Patent Document 2] Satoru Takagi and one other, “Information Retrieval with Graphical Map”, Journal of Information Processing Society of Japan, 2000, Vol. 41, No. 4, pp. 357-362.
[Non-Patent Document 3] Kaoru Hiramatsu and one other, “An Augmented Web Space for Regional information Services”, Transactions of information Processing Society of Japan, database, 2000, Vol. 41, No. SIG6(TOD7), pp. 81-90.
[Non-Patent Document 4] Kaoru Hiramatsu and two others, “Web Search Extension based on Spatio-temporal Structure”, The 1.sup.st meeting of JSAI Special Interest Group on Semantic Web and Ontology, 2002, No. SIG-SWO-A201-08, The Japanese Society for Artificial Intelligence.
[Non-Patent Document 5] Hiroki Uematsu and four others, “Balog: Proposal of Use of Location-based Information in Web Log Environment”, The 6.sup.th meeting of Special Interest Group on Semantic Web and Ontology, 2004, No. SIG-SWO-A401-07, The Japanese Society for Artificial Intelligence.
[Non-Patent Document 6] Takeshi Karashima and two others, “Blog Map of Experiences: Extraction and Geographical Mapping of Visitor Experiences from Urban Blogs”, The Special Interest Group Notes of Information Processing Society of Japan, 2005, Vol. 2005, No. 67, 2005-DBS-137, pp. 47-53.
[Non-Patent Document 7] Taro Tezuka and one other, “Trajectory-based Presentation of Heterogeneous Spatio-temporal Content”, Web and Wireless Geographical Information Systems—W2GIS2005, Lecture Notes in Computer Science 3833, pp. 235-245, Springer-Verlag.
[Non-Patent Document 8] Taro Tezuka and one other, “Query-Free Browsing of Local Information based on Landmark Extraction from the Web” DBSJ Letters, 2005, Vol. 4, No. 1, pp. 141-144.
[Non-Patent Document 9] Joe Weakliam and two others, “Implicit interaction profiling for recommending spatial content” ACM GIS 2005, pp. 285-294.
[Non-Patent Document 10] Qiang Ma and two others, “Localness Degree of Web Pages and Its Applications from Page Content and Location Information”, The Special Interest Group Notes of Information Processing Society of Japan. 2002. Vol. 2002, No. 67, 2002-DBS-128-69, pp. 515-522.